It is frequently desired to supress noise in electrical and electronic circuits, usually relatively high frequency noise, and this is generally difficult and expensive. For example, it can be accomplished by the use of several stages of filters or other means which may be effective but which are unduly cumbersome or expensive, usually both. Accordingly there is a need for a noise supressor which is simple, inexpensive and easy to use. The present invention relates to such an inexpensive and simple element and to its use for noise supression in electronic circuits.
One of the problems with attenuation or suppression of noise in such circuits and devices is that relatively high frequency noise which needs to be supressed is often noise over a broad frequency range, and devices which cover these relatively broad bands are usually complex in design and at least are expensive to make. For example, in uses and applications where a few cents apiece is a significant additive cost, elaborate or multiple stage filters are at best inappropriate. One effort to overcome some of the problems and difficulties is shown, for example, in U.S. Pat. No. 3,781,740, wherein a choke is proposed for impulse-like interference voltages, the choke having two annular partial cores. While this may bring about a significant cost savings compared with previous ways of reducing noise, the element shown in that patent is still expensive in terms of many common usages and is more awkward to use than would be desirable.